Magneto-optical recording-reproducing method and apparatus utilizing domain wall displacement

Abstract

Disclosed herein is a magneto-optical recording-reproducing method, wherein a domain wall of a record mark is displaced on a recording medium, thereby conducting the reproduction of information, the method comprising the steps of reproducing the prescribed record signals recorded in the recording medium by plural stages of reproduction power to detect reproduction signals; differentiating the reproduction signals to detect differential signals; and determining the reproduction power on the basis of the amplitude values of the differential signals.

What is claimed is:  
     
       1. A magneto-optical reproducing method wherein information recorded on a recording medium is reproduced by displacing a domain wall, the method comprising the steps of: 
       reproducing prescribed record signals recorded in the recording medium by plural stages of reproduction power to detect reproduction signals;  
       differentiating reproduction signals detected in said reproducing step to detect differential signals; and  
       determining a reproduction power on the basis of amplitude values of the differential signals.  
     
     
       2. The method according to claim  1 , wherein in said determining step, a reproduction power at which an amplitude value reaches a maximum value is determined as said reproduction power. 
     
     
       3. The method according to claim  1 , wherein detection of said amplitude values is conducted by sampling envelope detection signals of said differential signals. 
     
     
       4. The method according to claim  1 , wherein said reproducing, differentiating and determining steps are conducted with respect to prescribed regions of the recording medium. 
     
     
       5. The method according to claim  2 , wherein in said determining step, reproduction power at which amplitude values of the differential signals reach a maximum value is detected repeatedly plural times, and an average value of the reproduction power detected by respective measurements is determined as a final reproduction power. 
     
     
       6. The method according to claim  2 , wherein in said determining step, a reproduction power closest to the reproduction power at which the amplitude of the reproduction signal reaches the maximum value is determined as a final reproduction power among reproduction power values at which the amplitude of the differential signals reaches a maximum value. 
     
     
       7. A magneto-optical reproducing apparatus wherein information recorded on a recording medium is reproduced by displacing a domain wall, the apparatus comprising: 
       means for reproducing prescribed record signals recorded in the recording medium by plural stages of reproduction power to detect reproduction signals;  
       means for differentiating reproduction signals to detect differential signals; and  
       means for determining a reproduction power on the basis of amplitude values of the differential signals.